Patent GB-415753-A (GB)
Title: New azo dyestuffs and the application thereof
IPC: C09B29/08
Filed: 1932-11-30
Abstract: Azo dyes, suitable for dyeing wool and silk and capable of undergoing lactamisation in substance or on the fibre, having the general formula <FORM:0415753/IV/1> in which R is an aryl residue free from solubilizing groups, X is O or S, and Y is <FORM:0415753/IV/2> (R1 and R<2> = H or alkyl) are obtained by (1) diazotizing an amine R--NH2 and coupling with a compound (other than an o-aminophenylthioglycollic acid or a 4-alkyl- or 4-alkoxy-2-aminophenylglycollic acid) of the general formula <FORM:0415753/IV/3> or (2) diazotizing a compound of the general formula <FORM:0415753/IV/4> in which Z is a group, such as a nitro or acylamino group, readily convertible into NH2, coupling with a suitable component and finally converting the group Z into NH2.  The benzene nucleus may, in either case carry further non-solubilizing substituents.  The following examples are specified.  (1) The nitro groups of the dyestuffs 2-nitro-4-aminophenylthioglycollic acid (cf. Specification 406,281) --> the p-anisidide or the anilide of 2 : 3-oxynaphthoic acid or the p-anisidide of acetoacetic acid are reduced with sodium sulphide to obtain red, red or yellow dyestuffs respectively; when the dyeings on wool or silk are lactamized by treatment with dilute mineral acid, the fastness to mild alkaline washing is much increased; a table is also given showing the shades of the lactamized dyeings with the use as coupling components of the 5<1>-chloro-2<1>-toluidide of 2 : 3-oxynaphthoic acid, acetoacetanilide, the p-chloranilide of 2 : 3-hydroxycarbazolecarboxylic acid, b -naphthol, 1-phenyl-3 - methyl - 5 - pyrazolone, 1 : 5 - dihydroxynaphthalene and 2 : 4-dihydroxyquinoline.  (2) The nitro group of the dyestuff 2-nitro-5-aminophenylthioglycollic acid --> the p-anisidide of 2 : 3-oxynaphthoic acid is reduced with sodium sulphide to obtain a dyestuff which dyes wool as described in (7) below; a table is also given showing the shades of the primary and the lactamized dyeings with the corresponding dyes having as initial diazo components 2 - nitro - 4 - aminophenylthiolactic acid, 2 - nitro - 4 - aminophenylglycollic acid, 2-nitro-4-aminophenyllactic acid, 4-chloro-2-nitro-5-aminophenylthiolisobutyric acid, and the 4-chloro-, 4-methyl- and 4-methoxy-derivatives of 2-nitro-5-aminophenylthioglycollic acid.  (3) The coupling component in (1) is replaced by the p-anisidide of 2 : 3-oxycarbazolecarboxylic acid; the product dyes wool or silk a deep chocolate brown which becomes faster to washing on lactamization.  (4) The nitro group of the dyestuff 4-chloro-2-nitro-5-aminophenylthioglycollic acid --> 2<1> : 3<1>-oxynaphthoyl - 4 - bromo - o - anisidine is reduced with sodium sulphide; the product gives on cotton or a wool-cotton union a dull bordeaux shade which becomes red on lactamization. (5) The dyestuff 1 : 5-aminonaphthol --> 2-aminophenylglycollic acid is produced in substance.  (6) Wool or silk is steeped for 5--10 minutes in a boiling solution of the first-mentioned aminoazo dyestuff of (1) above and acetic acid is added slowly until maximum adsorption of the colour is attained; the goods are then freed from superfluous liquor, immersed for 10 minutes in 5 per cent sulphuric acid at 90 DEG  C. to effect the lactamization, rinsed, washed and dried to obtain a bright red dyeing of enhanced fastness to washing with a warm dilute solution of sodium carbonate.  (7) Wool or silk is treated for 30 minutes at 85 DEG  C. in a solution of the first-mentioned aminoazo dyestuff of (2) above containing ammonium acetate and the resulting violet dyeing is lactamized by immersing the goods for 30 minutes in 5 per cent sulphuric or hydrochloric acid at 60--70 DEG  C. to obtain a bordeaux shade fast to washing and potting.  (8) Cotton or a wool-cotton union is steeped for 30--45 minutes in a boiling solution of the dyestuff obtained by reducing the nitro group of the dyestuff 4-methoxy-2-nitro-5-amino-phenylthioglycollic acid --> the 5<1>-chloro-2<1>-toluidide of 2 : 3-oxynaphthoic acid; the resulting violet dyeing, on lactamization by immersion for 30 minutes in a 5 per cent solution of hydrochloric acid at 80 DEG  C. becomes brighter and faster to washing.  (9) Cotton or a wool-cotton union is steeped for 30 minutes in a boiling solution containing the dyestuff of (3) above, ammonia and ammonium acetate; the resulting brown dyeing is lactamized as in (8).  (10) Wool is steeped for 45 minutes in a boiling solution containing the dyestuff of (5) above, ammonia and ammonium acetate; the resulting dyeing is lactamized as in (8). Specifications 25,239/12, [Class 15 (ii)], and 377,739 also are referred to. p   2-Nitro-5-aminophenylthioglycollic acid and its 4-chloro-, 4-methyl- and 4-methoxy-derivatives are obtained by condensing 3-chloro-4-nitroacetanilide, 2 5-dichloro-4-nitroacetanilide, 4-chloro-5-nitroaceto-2-toluidine and 4-chloro-5 - nitroaceto - 2 - anisidine respectively with thioglycollic acid in alcoholic solution in presence of alkali.  4 - Chloro - 2 - nitro - 5 - aminophenylthioliso - butyric acid is obtained by condensing similarly 2 : 5 - dichloro - 4 - nitroacetanilide with a -mercaptoisobutyric acid.  2 - Nitro - 4 - aminophenylthiolactic acid is obtained by partially reducing with sodium sulphide the nitro groups of the product obtained by condensing 2 : 4-dinitrochloro-benzene with sodium hydrogen sulphide and condensing the resulting mercaptan with a -bromopropionic acid. 2-Nitro-4-aminophenyllactic acid is obtained by hydrolyzing the corresponding 4-acetylamino compound obtainable by nitrating the condensation product of p-acetylaminophenol with a -bromopropionic acid.